1. Field of the Invention
The present invention relates to a method and device for use in calibrating a fluid flow rate from a single discharge nozzle or multiple discharge nozzles used in connection with fluid sprayers.
2. Description of Related Art
Fluid in particular, agricultural sprayers are commonly outfitted with equipment enabling a liquid discharge rate to be varied according to the particular type of spraying to be performed. For example, the flow rates employed in herbicide application are low, relative to volume orchard spraying, which would be considered as being in the medium flow rate range. Higher flow rates are employed, for example, in high volume citrus spraying. The agricultural sprayer equipment may have variable speed pumps, variable opening flow rate valves, and may have more than one set of nozzles which can be used to alter spraying parameters, such as pressure and speed, in order to permit adjustment of the sprayer to a desired liquid flow discharge rate.
Heretofore, various devices and methods have been used in measuring liquid flow rates of, and in calibrating the liquid discharge of, spray equipment. As used herein, with respect to spray equipment, the word "calibrate" refers to a measuring of a liquid flow rate and adjusting spraying parameters necessary to obtain the desired application rate. The spray calibrators or calibration devices referred to herein are generally designed to perform only the flow rate measurements to assist an operator in determining do not themselves have the capability to make such adjustments on the spraying equipment.
Particularly in the field of agricultural sprayers, the use of calibrating devices is desirable, and in some instances necessary, in order to avoid overspraying or underspraying a desired quantity of, for example, a pesticide or herbicide. Calibrating devices known in the agricultural spraying art have generally been designed to measure liquid flow from only a single nozzle. One disadvantage of such calibrators is that two common types of agricultural sprayers, the boom-type sprayer and the air-blast sprayer, discharge liquid simultaneously from a plurality of individual nozzles, which are likely to be discharging the liquid at slightly varying rates. The calibrators therefore are essentially unable to measure a total liquid discharge flow rate from all nozzles for use in calibrating the sprayer.
Spray calibrators are also known in which a receptacle is attached to a nozzle to collect the liquid discharged from that nozzle in a measured time period. The flow rate is determined by dividing the volume of liquid collected by the measured time to collect the liquid. An example of such a calibrator is shown in U.S. Pat. No. 4,409,845 to Stufflebam et al. Such calibrators suffer from the disadvantage that the erratic start-up liquid flow rate normally evidenced in spraying equipment is included in the calculation of the flow rate. The steady state flow rate, which is of more interest to the operator, cannot accurately be calculated by such a system.
Yet another drawback of some of the known calibrating devices is that the design of such calibrating devices does not allow recovery of the liquid discharged during calibration. In order to liquid discharged during calibration. In order to conserve more expensive liquids containing active ingredients, such calibrating devices are designed to use water as the liquid discharged and measured in the calibration process, and the pesticide or other liquid is not dispensed until actual operation. Such substitution of liquids may adversely impact the accuracy of the measurement and it is therefore desirable to use the actual liquid which is to be sprayed during operation for the calibration process as well.
Known calibration devices range from the relative complexity of computerized flow meters to the relative simiplicity of the plastic bag calibrator described in the Stufflebam patent. As indicated previously, these calibration devices are generally employed to measure liquid flow rate from a single nozzle and not from a multiple nozzle discharge. Further, devices such as that disclosed in the Stufflebam patent are generally not capable of measuring a steady state flow rate, in that a sprayer will generally not discharge fluid at the same rate during initial start-up as it will during the remainder of normal operation.
It is therefore a principal object of the present invention to provide a spray calibration device which is capable of measuring flow rate of actual liquid, and particularly a steady state flow rate, from an entire bank of nozzles situated on an agricultural sprayer, such as a boom sprayer.
It is a further object of the present invention to provide an inexpensive and easy-to-use spray calibration device for measuring a combined flow rate of a liquid discharged from a plurality of spray nozzles.
It is a further object of the present invention to provide a spray calibration device which is capable of measuring a liquid flow rate of a liquid discharge from either a plurality of nozzles or a single nozzle.
It is yet a further object of the present invention to provide a spray calibration device which permits recovery and reuse of the liquid sprayed during the calibration process.
Another object of the present invention is to provide a spray calibration device having a receptacle having at least one internal partition, the partition dividing the receptacle into at least two compartments, and further having a means for selectively directing the liquid collected into the two compartments.
It is yet another object of the present invention to provide a manifold assembly having a plurality of tubes extending therefrom for connection to a plurality of spray nozzles, the manifold further having an outlet tube for attachment to an inlet port on a liquid collection receptacle.